1. Field of the Invention
The present invention relates to a polyester resin composition which has been improved in impact resistance, particularly impact resistance at low temperatures while maintaining its mechanical properties such as strength, stiffness and the like, and also which gives molded products having excellent appearance.
2. Description of the Related Art
Hitherto, there have been proposed many methods for improving the mechanical properties (e.g. impact resistance) of thermoplastic polyester resins. Among these, a method of blending a polyester and an .alpha.-olefin/glycidyl methacrylate/vinyl acetate copolymer, described in Japanese Patent Application Kokoku No. 58-47419 and U.S. Pat. No. 4,172,859, is a relatively excellent method. Also, the present applicants disclosed a method of adding a polyorganosiloxane graft copolymer to a polyester in Japanese Patent Application Kokai No. 2-150446. These methods are both relatively good, but their improvement in impact strength is still insufficient. Further, the present applicants proposed a method of adding a particular polyorganosiloxane rubber and a particular organic silane compound to a polyester in EP-A2-393,616. This method is in a satisfactory level in terms of development of impact strength, but there still remains a problem that the appearance of molded products obtained therefrom is poor.